State targets natives and children for first round of experimental live vaccines

A nurse injects an experimental flu vaccine into the arm of a volunteer during a clinical trial.

Five-to-40-year-olds and Canada’s aboriginal communities should be the first to get vaccinated against human swine flu, experts say as Canadian officials decide who gets priority for the flu shots.

Under Canada’s official pandemic plan, the entire population would ultimately be immunized against the H1N1 swine flu.

But the vaccine will become available in batches, meaning the entire population can’t be vaccinated at once. It might take four or five months to get all the vaccine we’re going to get, during which time a second wave of swine flu may well be underway.

The Public Health Agency of Canada is working on a priority list, deciding where the first batches should go, and who should get the injections first. All provinces and territories would be expected to follow the national prioritization scheme.

“It doesn’t mean they’re all getting sick and need to be hospitalized, but they’re getting significant illness,” said Dr. Noni MacDonald, a leader in pediatric infectious diseases and a professor of pediatrics at Dalhousie University in Halifax.

British researchers reported last week that targeting children first would protect not only them, but also unvaccinated adults.

As well, children “are known to be really important for transmitting flu,” said Earl Brown, executive director of the Emerging Pathogens Research Centre at the University of Ottawa.

“They’re important for the cycle of infection. They tend to be naive as far as not having flu antibodies in their system before. And really young kids, their immune systems aren’t fully mature.

“Children tend to be hit, and they can be hit harder,” Brown said.

Canada’s aboriginal communities also appear to be getting more serious infections. Crowded, poorly ventilated housing and poor access to high-quality running water and sanitization are some of the factors being blamed. Aboriginals also have higher rates of asthma, chronic lung disease, obesity and diabetes — the very diseases early data suggests puts people at higher risk of life-threatening complications from swine flu.

The Public Health Agency of Canada says that no decisions have yet been made about who would get priority first.

There will be limited information about any vaccine’s safety before immunization campaigns are rolled out across the country.

“We usually do research in healthy adults before we do it in children, because this is a new vaccine, and you want to be sure that it’s safe and effective before you give it to vulnerable populations, or populations who don’t have full capacity to make an informed decision about getting it or not,” said Dr. Joanne Langley, of Health Canada’s National Advisory Committee on Immunization.